Aptitude - Ratio and Proportion - Discussion
Discussion Forum : Ratio and Proportion - General Questions (Q.No. 9)
9.
The sum of three numbers is 98. If the ratio of the first to second is 2 :3 and that of the second to the third is 5 : 8, then the second number is:
Answer: Option
Explanation:
Let the three parts be A, B, C. Then,
| A : B = 2 : 3 and B : C = 5 : 8 = |  |
5 x | 3 |  |
: | |
8 x | 3 | |
= 3 : | 24 |
| 5 | 5 | 5 |
 A : B : C = 2 : 3 : |
24 | = 10 : 15 : 24 |
| 5 |
| B = |
|
98 x | 15 | |
= 30. |
| 49 |
Discussion:
122 comments Page 3 of 13.
Murali said:
1 decade ago
If a:b:c=2:3:5 then the ratio of (b+c)/4:(c+a)/4:(a+b)/4 is?
Can any one give answer for this....
Can any one give answer for this....
RISHIKESH said:
1 decade ago
Thanks alisha.
Deepi said:
1 decade ago
Hi Guys,
I have a shortcut method like this kind of problems see this
a:b:c can be calculated easily from a:b and b:c just multiply as shown below
a:b
b:c
-------
a*b:b*b:b*c
So from the problem 2:3 is a:b and 5:8 is b:c
2:3
5:8
-------
2*5:3*5:3*8
answer is 10:15:24
Here given is sum of three number is 98.
that is 10+15+24=49
49=98
15=? => (15*98)/49 = 30.
I have a shortcut method like this kind of problems see this
a:b:c can be calculated easily from a:b and b:c just multiply as shown below
a:b
b:c
-------
a*b:b*b:b*c
So from the problem 2:3 is a:b and 5:8 is b:c
2:3
5:8
-------
2*5:3*5:3*8
answer is 10:15:24
Here given is sum of three number is 98.
that is 10+15+24=49
49=98
15=? => (15*98)/49 = 30.
(1)
Nisha said:
1 decade ago
Thanks kalpa.
Deepi said:
1 decade ago
SEE This carefully
a:b1
- b2:c
-----------
a*b2:b1*b2:b1*c=a:b:c
a:b1
- b2:c
-----------
a*b2:b1*b2:b1*c=a:b:c
JAY NAMDEV said:
1 decade ago
There are 150 students in a class, we have only 58 rupees, if we distribute 25p and 50p amongst girls and boys respectively then what no of girls?
Veena said:
1 decade ago
x:y=2:3 --->1
y:z=5:8 --->2
multiply with 5 in equation 1
10:15
in equation 2 multiply with 3
15:24
10:15:24
15--?
49--98
15/49x98=30
y:z=5:8 --->2
multiply with 5 in equation 1
10:15
in equation 2 multiply with 3
15:24
10:15:24
15--?
49--98
15/49x98=30
POORNI said:
1 decade ago
THANKS APARNA
Rajkumar said:
1 decade ago
General formula
A:B
B:C
---------------
A*B : B*B : B*C
----------------
A*B + B*B + B*C = sum
Then total should be divided with this sum
Ans = total / sum
This ans should be multiplied with each ratios to get a desired number
In the same way
2:3
5:8
-------
10:15:24 (2*5 : 3*15 : 3*8)
Then adding 10+15+24 gives 49
This 49 divides 98
98 / 49 = 2
B = 2*15 = 30
Similarly
A = 2 * 10 = 20
C = 2 * 24 = 48
A:B
B:C
---------------
A*B : B*B : B*C
----------------
A*B + B*B + B*C = sum
Then total should be divided with this sum
Ans = total / sum
This ans should be multiplied with each ratios to get a desired number
In the same way
2:3
5:8
-------
10:15:24 (2*5 : 3*15 : 3*8)
Then adding 10+15+24 gives 49
This 49 divides 98
98 / 49 = 2
B = 2*15 = 30
Similarly
A = 2 * 10 = 20
C = 2 * 24 = 48
Sana said:
1 decade ago
Kalpa and Abhishek gave best n easy methods, thank you :).
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